Let baksmali infer the api level when possible

baksmali/src/main/java/org/jf/baksmali/DexInputCommand.java

@@ -55,7 +55,7 @@ public abstract class DexInputCommand extends Command {
     @Parameter(names = {"-a", "--api"},
             description = "The numeric api level of the file being disassembled.")
     @ExtendedParameter(argumentNames = "api")
-    public int apiLevel = 15;
+    public int apiLevel = -1;
 
     @Parameter(description = "A dex/apk/oat/odex file. For apk or oat files that contain multiple dex " +
             "files, you can specify the specific entry to use as if the apk/oat file was a directory. " +
@@ -125,6 +125,11 @@ public abstract class DexInputCommand extends Command {
             dexEntry = input.substring(file.getPath().length() + 1);
         }
 
+        Opcodes opcodes = null;
+        if (apiLevel != -1) {
+            opcodes = Opcodes.forApi(apiLevel);
+        }
+
         if (!Strings.isNullOrEmpty(dexEntry)) {
             boolean exactMatch = false;
             if (dexEntry.length() > 2 && dexEntry.charAt(0) == '"' && dexEntry.charAt(dexEntry.length() - 1) == '"') {
@@ -135,13 +140,13 @@ public abstract class DexInputCommand extends Command {
             inputEntry = dexEntry;
 
             try {
-                dexFile = DexFileFactory.loadDexEntry(file, dexEntry, exactMatch, Opcodes.forApi(apiLevel));
+                dexFile = DexFileFactory.loadDexEntry(file, dexEntry, exactMatch, opcodes);
             } catch (IOException ex) {
                 throw new RuntimeException(ex);
             }
         } else {
             try {
-                dexFile = DexFileFactory.loadDexFile(file, Opcodes.forApi(apiLevel));
+                dexFile = DexFileFactory.loadDexFile(file, opcodes);
             } catch (IOException ex) {
                 throw new RuntimeException(ex);
             }

dexlib2/src/main/java/org/jf/dexlib2/DexFileFactory.java

@@ -58,7 +58,7 @@ import java.util.List;
 public final class DexFileFactory {
 
     @Nonnull
-    public static DexBackedDexFile loadDexFile(@Nonnull String path, @Nonnull Opcodes opcodes) throws IOException {
+    public static DexBackedDexFile loadDexFile(@Nonnull String path, @Nullable Opcodes opcodes) throws IOException {
         return loadDexFile(new File(path), opcodes);
     }
 
@@ -79,7 +79,7 @@ public final class DexFileFactory {
      * in a zip file is not a valid dex file
      */
     @Nonnull
-    public static DexBackedDexFile loadDexFile(@Nonnull File file, @Nonnull Opcodes opcodes) throws IOException {
+    public static DexBackedDexFile loadDexFile(@Nonnull File file, @Nullable Opcodes opcodes) throws IOException {
         if (!file.exists()) {
             throw new DexFileNotFoundException("%s does not exist", file.getName());
         }
@@ -176,7 +176,7 @@ public final class DexFileFactory {
      * @throws MultipleMatchingDexEntriesException If multiple entries match the given dexEntry
      */
     public static DexBackedDexFile loadDexEntry(@Nonnull File file, @Nonnull String dexEntry,
-                                                boolean exactMatch, @Nonnull Opcodes opcodes) throws IOException {
+                                                boolean exactMatch, @Nullable Opcodes opcodes) throws IOException {
         if (!file.exists()) {
             throw new DexFileNotFoundException("Container file %s does not exist", file.getName());
         }
@@ -456,10 +456,6 @@ public final class DexFileFactory {
             }
             return null;
         }
-
-        @Nonnull @Override public Opcodes getOpcodes() {
-            return dexFile.getOpcodes();
-        }
     }
 
     public static class FilenameVdexProvider implements VdexProvider {

dexlib2/src/main/java/org/jf/dexlib2/Opcodes.java

@@ -64,6 +64,11 @@ public class Opcodes {
         return new Opcodes(NO_VERSION, artVersion);
     }
 
+    @Nonnull
+    public static Opcodes forDexVersion(int dexVersion) {
+        return new Opcodes(VersionMap.mapDexVersionToApi(dexVersion) , NO_VERSION);
+    }
+
     /**
      * @return a default Opcodes instance for when the exact Opcodes to use doesn't matter or isn't known
      */

dexlib2/src/main/java/org/jf/dexlib2/VersionMap.java

@@ -34,6 +34,19 @@ package org.jf.dexlib2;
 public class VersionMap {
     public static final int NO_VERSION = -1;
 
+    public static int mapDexVersionToApi(int dexVersion) {
+        if (dexVersion == 35) {
+            return 23;
+        }
+        if (dexVersion == 37) {
+            return 25;
+        }
+        if (dexVersion == 38) {
+            return 27;
+        }
+        throw new RuntimeException("Unsupported dex version " + dexVersion);
+    }
+
     public static int mapArtVersionToApi(int artVersion) {
         if (artVersion >= 124) {
             return 26;

dexlib2/src/main/java/org/jf/dexlib2/dexbacked/DexBackedDexFile.java

@@ -71,13 +71,20 @@ public class DexBackedDexFile extends BaseDexBuffer implements DexFile {
     private final int classStartOffset;
     private final int mapOffset;
 
-    protected DexBackedDexFile(@Nonnull Opcodes opcodes, @Nonnull byte[] buf, int offset, boolean verifyMagic) {
+    protected DexBackedDexFile(@Nullable Opcodes opcodes, @Nonnull byte[] buf, int offset, boolean verifyMagic) {
         super(buf, offset);
 
-        this.opcodes = opcodes;
+        int dexVersion;
-
         if (verifyMagic) {
-            DexUtil.verifyDexHeader(buf, offset);
+            dexVersion = DexUtil.verifyDexHeader(buf, offset);
+        } else {
+            dexVersion = HeaderItem.getVersion(buf, offset);
+        }
+
+        if (opcodes == null) {
+            this.opcodes = Opcodes.forDexVersion(dexVersion);
+        } else {
+            this.opcodes = opcodes;
         }
 
         stringCount = readSmallUint(HeaderItem.STRING_COUNT_OFFSET);
@@ -95,20 +102,20 @@ public class DexBackedDexFile extends BaseDexBuffer implements DexFile {
         mapOffset = readSmallUint(HeaderItem.MAP_OFFSET);
     }
 
-    public DexBackedDexFile(@Nonnull Opcodes opcodes, @Nonnull BaseDexBuffer buf) {
+    public DexBackedDexFile(@Nullable Opcodes opcodes, @Nonnull BaseDexBuffer buf) {
         this(opcodes, buf.buf, buf.baseOffset);
     }
 
-    public DexBackedDexFile(@Nonnull Opcodes opcodes, @Nonnull byte[] buf, int offset) {
+    public DexBackedDexFile(@Nullable Opcodes opcodes, @Nonnull byte[] buf, int offset) {
         this(opcodes, buf, offset, false);
     }
 
-    public DexBackedDexFile(@Nonnull Opcodes opcodes, @Nonnull byte[] buf) {
+    public DexBackedDexFile(@Nullable Opcodes opcodes, @Nonnull byte[] buf) {
         this(opcodes, buf, 0, true);
     }
 
     @Nonnull
-    public static DexBackedDexFile fromInputStream(@Nonnull Opcodes opcodes, @Nonnull InputStream is)
+    public static DexBackedDexFile fromInputStream(@Nullable Opcodes opcodes, @Nonnull InputStream is)
             throws IOException {
         DexUtil.verifyDexHeader(is);
 

dexlib2/src/main/java/org/jf/dexlib2/dexbacked/OatFile.java

@@ -177,10 +177,6 @@ public class OatFile extends BaseDexBuffer implements MultiDexContainer<OatDexFi
         return Arrays.asList(bcp.split(":"));
     }
 
-    @Nonnull @Override public Opcodes getOpcodes() {
-        return opcodes;
-    }
-
     @Nonnull
     public List<OatDexFile> getDexFiles() {
         return new AbstractForwardSequentialList<OatDexFile>() {

dexlib2/src/main/java/org/jf/dexlib2/dexbacked/ZipDexContainer.java

@@ -58,23 +58,18 @@ import java.util.zip.ZipFile;
 public class ZipDexContainer implements MultiDexContainer<ZipDexFile> {
 
     private final File zipFilePath;
-    private final Opcodes opcodes;
+    @Nullable private final Opcodes opcodes;
 
     /**
      * Constructs a new ZipDexContainer for the given zip file
      *
      * @param zipFilePath The path to the zip file
-     * @param opcodes The Opcodes instance to use when loading dex files from this container
      */
-    public ZipDexContainer(@Nonnull File zipFilePath, @Nonnull Opcodes opcodes) {
+    public ZipDexContainer(@Nonnull File zipFilePath, @Nullable Opcodes opcodes) {
         this.zipFilePath = zipFilePath;
         this.opcodes = opcodes;
     }
 
-    @Nonnull @Override public Opcodes getOpcodes() {
-        return opcodes;
-    }
-
     /**
      * Gets a list of the names of dex files in this zip file.
      *
@@ -147,7 +142,7 @@ public class ZipDexContainer implements MultiDexContainer<ZipDexFile> {
 
         private final String entryName;
 
-        protected ZipDexFile(@Nonnull Opcodes opcodes, @Nonnull byte[] buf, @Nonnull String entryName) {
+        protected ZipDexFile(@Nullable Opcodes opcodes, @Nonnull byte[] buf, @Nonnull String entryName) {
             super(opcodes, buf, 0);
             this.entryName = entryName;
         }

dexlib2/src/main/java/org/jf/dexlib2/iface/MultiDexContainer.java

@@ -31,8 +31,6 @@
 
 package org.jf.dexlib2.iface;
 
-import org.jf.dexlib2.Opcodes;
-
 import javax.annotation.Nonnull;
 import javax.annotation.Nullable;
 import java.io.IOException;
@@ -55,11 +53,6 @@ public interface MultiDexContainer<T extends DexFile> {
      */
     @Nullable T getEntry(@Nonnull String entryName) throws IOException;
 
-    /**
-     * @return the Opcodes instance associated with this MultiDexContainer
-     */
-    @Nonnull Opcodes getOpcodes();
-
     /**
      * This class represents a dex file that is contained in a MultiDexContainer
      */

dexlib2/src/main/java/org/jf/dexlib2/util/DexUtil.java

@@ -50,11 +50,12 @@ public class DexUtil {
      * The inputStream must support mark(), and will be reset to initial position upon exiting the method
      *
      * @param inputStream An input stream that is positioned at a dex header
+     * @return The dex version
      * @throws NotADexFile If the file is not a dex file
      * @throws InvalidFile If the header appears to be a dex file, but is not valid for some reason
      * @throws UnsupportedFile If the dex header is valid, but uses unsupported functionality
      */
-    public static void verifyDexHeader(@Nonnull InputStream inputStream) throws IOException {
+    public static int verifyDexHeader(@Nonnull InputStream inputStream) throws IOException {
         if (!inputStream.markSupported()) {
             throw new IllegalArgumentException("InputStream must support mark");
         }
@@ -68,7 +69,7 @@ public class DexUtil {
             inputStream.reset();
         }
 
-        verifyDexHeader(partialHeader, 0);
+        return verifyDexHeader(partialHeader, 0);
     }
 
     /**
@@ -76,11 +77,12 @@ public class DexUtil {
      *
      * @param buf A byte array containing at least the first 44 bytes of a dex file
      * @param offset The offset within the array to the dex header
+     * @return The dex version
      * @throws NotADexFile If the file is not a dex file
      * @throws InvalidFile If the header appears to be a dex file, but is not valid for some reason
      * @throws UnsupportedFile If the dex header is valid, but uses unsupported functionality
      */
-    public static void verifyDexHeader(@Nonnull byte[] buf, int offset) {
+    public static int verifyDexHeader(@Nonnull byte[] buf, int offset) {
         int dexVersion = HeaderItem.getVersion(buf, offset);
         if (dexVersion == -1) {
             StringBuilder sb = new StringBuilder("Not a valid dex magic value:");
@@ -102,6 +104,8 @@ public class DexUtil {
         if (endian != HeaderItem.LITTLE_ENDIAN_TAG) {
             throw new InvalidFile(String.format("Invalid endian tag: 0x%x", endian));
         }
+
+        return dexVersion;
     }
 
     /**

dexlib2/src/test/java/org/jf/dexlib2/DexEntryFinderTest.java

@@ -223,9 +223,5 @@ public class DexEntryFinderTest {
             }
             return null;
         }
-
-        @Nonnull @Override public Opcodes getOpcodes() {
-            return Opcodes.getDefault();
-        }
     }
 }